BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuPernicious anemiaMacrocytic achylic anemia; Congenital pernicious anemia; Juvenile pernicious anemia; Vitamin B12 deficiency (malabsorption); Anemia - intrinsic factor; Anemia - IF; Anemia - atrophic gastritis; Biermer anemia; Addison anemiaAnemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types of anemia.AnemiaAnemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Different type...ImageRead Article Now Book Mark Article Pernicious anemia is a decrease in red blood cells that occurs when the intestines cannot properly absorb vitamin B12. Causes Related video goes here for no-HTML5 browsersPernicious anemia is a type of vitamin B12 anemia. The body needs vitamin B12 to make red blood cells. You get this vitamin from eating foods such as meat, poultry, shellfish, eggs, and dairy products. A special protein, called intrinsic factor (IF), binds vitamin B12 so that it can be absorbed in the intestines. This protein is released by cells in the stomach. When the stomach does not make enough intrinsic factor, the intestine cannot properly absorb vitamin B12.Common causes of pernicious anemia include:Weakened stomach lining (atrophic gastritis) An autoimmune condition in which the body's immune system attacks the actual intrinsic factor protein or the cells in the lining of your stomach that make it. In rare cases, pernicious anemia is passed down through families. This is called congenital pernicious anemia. Babies with this type of anemia do not make enough intrinsic factor. Or they cannot properly absorb vitamin B12 in the small intestine. In adults, symptoms of pernicious anemia are usually not seen until after age 30. The average age of diagnosis is age 60. You are more likely to develop this disease if you:Are Scandinavian or Northern European Have a family history of the condition Certain diseases can also raise your risk. They include:Addison disease Addison diseaseAddison disease is a disorder that causes the adrenal glands to not produce enough hormones.ImageRead Article Now Book Mark Article Graves disease Graves diseaseGraves disease is an autoimmune disorder that leads to an overactive thyroid gland (hyperthyroidism). An autoimmune disorder is a condition that occ...ImageRead Article Now Book Mark Article Hypoparathyroidism HypoparathyroidismHypoparathyroidism is a disorder in which the parathyroid glands in the neck do not produce enough parathyroid hormone (PTH).ImageRead Article Now Book Mark Article Hypothyroidism HypothyroidismHypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....ImageRead Article Now Book Mark Article Myasthenia gravis Myasthenia gravisMyasthenia gravis is a neuromuscular disorder. Neuromuscular disorders involve the muscles and the nerves that control them.ImageRead Article Now Book Mark Article Loss of normal function of ovaries before 40 years of age (primary ovarian failure) Type 1 diabetes Type 1 diabetesType 1 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood.ImageRead Article Now Book Mark Article Testicular dysfunction Vitiligo VitiligoVitiligo is a skin condition in which there is a loss of color (pigment) from areas of skin. This results in uneven white patches that have no pigme...ImageRead Article Now Book Mark Article Sjögren syndrome Sjögren syndromeSjögren syndrome is an autoimmune disorder in which the glands that produce tears and saliva are destroyed. This causes dry mouth and dry eyes. The...ImageRead Article Now Book Mark Article Hashimoto disease Hashimoto diseaseChronic thyroiditis is caused by a reaction of the immune system against the thyroid gland. It often results in reduced thyroid function (hypothyroi...ImageRead Article Now Book Mark Article Celiac diseaseCeliac diseaseCeliac disease is an autoimmune condition that damages the lining of the small intestine. This damage comes from a reaction to eating gluten. This ...ImageRead Article Now Book Mark Article Pernicious anemia can also occur after gastric bypass surgery. Symptoms Some people do not have symptoms. Symptoms may be mild. They may include:Diarrhea or constipation DiarrheaDiarrhea is when you pass loose or watery stool.ImageRead Article Now Book Mark Article Nausea Vomiting Fatigue, lack of energy, or lightheadedness when standing up or with exertion FatigueFatigue is a feeling of weariness, tiredness, or lack of energy.Read Article Now Book Mark Article Loss of appetite Loss of appetiteA decreased appetite is when your desire to eat is reduced. The medical term for a loss of appetite is anorexia.Read Article Now Book Mark Article Pale skin (mild jaundice) Shortness of breath, mostly during exercise Shortness of breathBreathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough airImageRead Article Now Book Mark Article Heartburn Swollen, red tongue or bleeding gums If you have a low vitamin B12 level for a long time, you can have nervous system damage. Symptoms may include:Confusion ConfusionConfusion is the inability to think as clearly or quickly as you normally do. You may feel disoriented and have difficulty paying attention, remembe...ImageRead Article Now Book Mark Article Short-term memory loss Depression DepressionDepression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for shor...ImageRead Article Now Book Mark Article Loss of balance Numbness and tingling in the hands and feet Problems concentrating Irritability Hallucinations HallucinationsHallucinations involve sensing things such as visions, sounds, or smells that seem real but are not. These things are created by the mind.Read Article Now Book Mark Article Delusions Optic nerve atrophyOptic nerve atrophyOptic nerve atrophy is damage to the optic nerve. The optic nerve carries images of what the eye sees to the brain.ImageRead Article Now Book Mark Article Exams and Tests Your health care provider will perform a physical exam. Tests that may be done include: Complete blood count (CBC) Complete blood count (CBC)A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...ImageRead Article Now Book Mark Article Reticulocyte count Reticulocyte countReticulocytes are slightly immature red blood cells. A reticulocyte count is a blood test that measures the amount of these cells in the blood....ImageRead Article Now Book Mark Article Lactate dehydrogenase (LDH) level Lactate dehydrogenase (LDH)Lactate dehydrogenase (LDH) is a protein that helps produce energy in the body. An LDH test measures the amount of LDH in the blood.Read Article Now Book Mark Article Serum bilirubin Serum bilirubinThe bilirubin blood test measures the level of bilirubin in the blood. Bilirubin is a yellowish pigment found in bile, a fluid made by the liver. Bi...ImageRead Article Now Book Mark Article Serum methylmalonic acid (MMA) level Serum methylmalonic acid (MMAThe methylmalonic acid blood test measures the amount of methylmalonic acid in the blood.ImageRead Article Now Book Mark Article Homocysteine level (amino acid found in blood) Homocysteine level (amino acid found in...Homocystinuria is a genetic disorder that affects the metabolism of the amino acid methionine. Amino acids are the building blocks of all proteins i...ImageRead Article Now Book Mark Article Serum vitamin B12 level Serum vitamin B12 levelThe vitamin B12 level is a blood test that measures how much vitamin B12 is in your blood.Read Article Now Book Mark Article Levels of antibodies against IF or the cells that make IF Treatment The goal of treatment is to increase your vitamin B12 level: Treatment involves a shot of vitamin B12 once a month. People with severely low levels of B12 may need more shots in the beginning. Some people may be adequately treated by taking large doses of vitamin B12 supplements by mouth. A certain type of vitamin B12 may be given through the nose. Outlook (Prognosis) Most people often do well with treatment.It is important to start treatment early. Nerve damage can be permanent if treatment does not start within 6 months of symptoms. Possible Complications People with pernicious anemia may have gastric polyps. They are also more likely to develop gastric cancer and gastric carcinoid tumors.Gastric cancerStomach cancer is cancer that starts in the stomach.ImageRead Article Now Book Mark Article People with pernicious anemia are more likely to have fractures of the back, upper leg, and upper forearm.Brain and nervous system problems may continue or be permanent if treatment is delayed.A woman with a low B12 level may have a false positive Pap smear. This is because vitamin B12 deficiency affects the way certain cells (epithelial cells) in the cervix look. When to Contact a Medical Professional Contact your provider if you have symptoms of vitamin B12 deficiency. Prevention There is no known way to prevent this type of vitamin B12 anemia. However, early detection and treatment can help reduce complications.Open ReferencesReferencesAntony AC. Megaloblastic anemias. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 40.Anusha V. Pernicious anemia/megaloblastic anemia. In: Kellerman RD, Rakel DP, Heidelbaugh JJ, Lee EM, eds. Conn's Current Therapy 2024. Philadelphia, PA: Elsevier; 2024:491-493.Elghetany MT, Banki K. Erythrocytic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 33.Means Jr. RT. Approach to the anemias. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 144.Stabler SP. Megaloblastic anemias. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 150.AllVideoImagesTogAnemiaAnimation Related video goes here for no-HTML5 browsersAnemia - Animation Do you feel tired and listless? Do you find your mind drifting during the day? Do you get dizzy or short of breath whenever you climb the stairs? There are a few possible reasons for the way you feel, but you could have anemia. You could even have anemia without noticing any symptoms at all. Anemia is a problem with hemoglobin, a substance in red blood cells that carries oxygen throughout your body. Without enough hemoglobin, your heart and other organs can't get the oxygen they need to work. When your organs slow down, you slow down and you start feeling tired and listless. Many different health conditions can cause anemia, from heavy blood loss during a woman's period, to pregnancy, to an underactive thyroid gland. Healthy red blood cells are made in your bone marrow, the soft tissue in the middle of your bones. Any disease that damages blood marrow, such as lymphoma or leukemia, can also affect your red blood cell production. Anemia can also be caused by an immune system problem that damages red blood cells, or surgery to the stomach or intestines. How do you know if you have anemia? You may feel tired, dizzy, and have trouble concentrating. You may get sick more often. People with anemia often complain of chest pain, headaches, or shortness of breath. Your skin might look pale, like you haven't seen the sun for months. Because these can also be symptoms of other conditions, your doctor will confirm that you have anemia by taking a blood test to check your red blood cell count and hemoglobin level. Blood tests can also look for problems that may be causing your anemia, such as a vitamin or iron deficiency. If you are anemic, it's very important to treat it. When your body isn't getting enough oxygen, it can starve vital organs like your heart. This can lead to a heart attack. How you treat anemia really depends on the cause. If the problem is with your bone marrow, you may take a medicine called erythropoietin, which will help your bone marrow make more red blood cells. If the problem is a vitamin or mineral deficiency, your doctor may prescribe iron, vitamin B12, or folic acid supplements. Or, you may need a blood transfusion to replace damaged red blood cells with healthy ones. How well you do really depends on what's causing your anemia. Call your doctor if you have any symptoms like fatigue or shortness of breath. Once your doctor can find and treat the cause of your anemia, you should have more energy and start feeling like your old self again.Megaloblastic anemia - view of red blood cells - illustration This picture shows large, dense, oversized, red blood cells (RBCs) that are seen in megaloblastic anemia. Megaloblastic anemia can occur when there is a deficiency of vitamin B-12.Megaloblastic anemia - view of red blood cellsillustrationAnemiaAnimation Related video goes here for no-HTML5 browsersAnemia - Animation Do you feel tired and listless? Do you find your mind drifting during the day? Do you get dizzy or short of breath whenever you climb the stairs? There are a few possible reasons for the way you feel, but you could have anemia. You could even have anemia without noticing any symptoms at all. Anemia is a problem with hemoglobin, a substance in red blood cells that carries oxygen throughout your body. Without enough hemoglobin, your heart and other organs can't get the oxygen they need to work. When your organs slow down, you slow down and you start feeling tired and listless. Many different health conditions can cause anemia, from heavy blood loss during a woman's period, to pregnancy, to an underactive thyroid gland. Healthy red blood cells are made in your bone marrow, the soft tissue in the middle of your bones. Any disease that damages blood marrow, such as lymphoma or leukemia, can also affect your red blood cell production. Anemia can also be caused by an immune system problem that damages red blood cells, or surgery to the stomach or intestines. How do you know if you have anemia? You may feel tired, dizzy, and have trouble concentrating. You may get sick more often. People with anemia often complain of chest pain, headaches, or shortness of breath. Your skin might look pale, like you haven't seen the sun for months. Because these can also be symptoms of other conditions, your doctor will confirm that you have anemia by taking a blood test to check your red blood cell count and hemoglobin level. Blood tests can also look for problems that may be causing your anemia, such as a vitamin or iron deficiency. If you are anemic, it's very important to treat it. When your body isn't getting enough oxygen, it can starve vital organs like your heart. This can lead to a heart attack. How you treat anemia really depends on the cause. If the problem is with your bone marrow, you may take a medicine called erythropoietin, which will help your bone marrow make more red blood cells. If the problem is a vitamin or mineral deficiency, your doctor may prescribe iron, vitamin B12, or folic acid supplements. Or, you may need a blood transfusion to replace damaged red blood cells with healthy ones. How well you do really depends on what's causing your anemia. Call your doctor if you have any symptoms like fatigue or shortness of breath. Once your doctor can find and treat the cause of your anemia, you should have more energy and start feeling like your old self again.Megaloblastic anemia - view of red blood cells - illustration This picture shows large, dense, oversized, red blood cells (RBCs) that are seen in megaloblastic anemia. Megaloblastic anemia can occur when there is a deficiency of vitamin B-12.Megaloblastic anemia - view of red blood cellsillustration Tests for Pernicious anemia Antiparietal cell antibody testVitamin B12 levelRelated Information Vitamin B12(Nutrition)Anemia(Condition)Endocrine glands(Special Topic)Type 1 diabetes(Condition)Hypoparathyroidism(Condition)Addison disease(Condition)Hypopituitarism(Condition)Graves disease(Condition)Chronic thyroiditis (Hashimoto disease)(Condition)Myasthenia gravis(Condition)Vitamins and Phytonutrients - InDepth(In-Depth)Anemia - InDepth(In-Depth)Diabetes - type 1 - InDepth(In-Depth) Review Date: 3/31/2024 Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.
Pernicious anemiaMacrocytic achylic anemia; Congenital pernicious anemia; Juvenile pernicious anemia; Vitamin B12 deficiency (malabsorption); Anemia - intrinsic factor; Anemia - IF; Anemia - atrophic gastritis; Biermer anemia; Addison anemiaAnemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types of anemia.AnemiaAnemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Different type...ImageRead Article Now Book Mark Article Pernicious anemia is a decrease in red blood cells that occurs when the intestines cannot properly absorb vitamin B12. Causes Related video goes here for no-HTML5 browsersPernicious anemia is a type of vitamin B12 anemia. The body needs vitamin B12 to make red blood cells. You get this vitamin from eating foods such as meat, poultry, shellfish, eggs, and dairy products. A special protein, called intrinsic factor (IF), binds vitamin B12 so that it can be absorbed in the intestines. This protein is released by cells in the stomach. When the stomach does not make enough intrinsic factor, the intestine cannot properly absorb vitamin B12.Common causes of pernicious anemia include:Weakened stomach lining (atrophic gastritis) An autoimmune condition in which the body's immune system attacks the actual intrinsic factor protein or the cells in the lining of your stomach that make it. In rare cases, pernicious anemia is passed down through families. This is called congenital pernicious anemia. Babies with this type of anemia do not make enough intrinsic factor. Or they cannot properly absorb vitamin B12 in the small intestine. In adults, symptoms of pernicious anemia are usually not seen until after age 30. The average age of diagnosis is age 60. You are more likely to develop this disease if you:Are Scandinavian or Northern European Have a family history of the condition Certain diseases can also raise your risk. They include:Addison disease Addison diseaseAddison disease is a disorder that causes the adrenal glands to not produce enough hormones.ImageRead Article Now Book Mark Article Graves disease Graves diseaseGraves disease is an autoimmune disorder that leads to an overactive thyroid gland (hyperthyroidism). An autoimmune disorder is a condition that occ...ImageRead Article Now Book Mark Article Hypoparathyroidism HypoparathyroidismHypoparathyroidism is a disorder in which the parathyroid glands in the neck do not produce enough parathyroid hormone (PTH).ImageRead Article Now Book Mark Article Hypothyroidism HypothyroidismHypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....ImageRead Article Now Book Mark Article Myasthenia gravis Myasthenia gravisMyasthenia gravis is a neuromuscular disorder. Neuromuscular disorders involve the muscles and the nerves that control them.ImageRead Article Now Book Mark Article Loss of normal function of ovaries before 40 years of age (primary ovarian failure) Type 1 diabetes Type 1 diabetesType 1 diabetes is a lifelong (chronic) disease in which there is a high level of sugar (glucose) in the blood.ImageRead Article Now Book Mark Article Testicular dysfunction Vitiligo VitiligoVitiligo is a skin condition in which there is a loss of color (pigment) from areas of skin. This results in uneven white patches that have no pigme...ImageRead Article Now Book Mark Article Sjögren syndrome Sjögren syndromeSjögren syndrome is an autoimmune disorder in which the glands that produce tears and saliva are destroyed. This causes dry mouth and dry eyes. The...ImageRead Article Now Book Mark Article Hashimoto disease Hashimoto diseaseChronic thyroiditis is caused by a reaction of the immune system against the thyroid gland. It often results in reduced thyroid function (hypothyroi...ImageRead Article Now Book Mark Article Celiac diseaseCeliac diseaseCeliac disease is an autoimmune condition that damages the lining of the small intestine. This damage comes from a reaction to eating gluten. This ...ImageRead Article Now Book Mark Article Pernicious anemia can also occur after gastric bypass surgery. Symptoms Some people do not have symptoms. Symptoms may be mild. They may include:Diarrhea or constipation DiarrheaDiarrhea is when you pass loose or watery stool.ImageRead Article Now Book Mark Article Nausea Vomiting Fatigue, lack of energy, or lightheadedness when standing up or with exertion FatigueFatigue is a feeling of weariness, tiredness, or lack of energy.Read Article Now Book Mark Article Loss of appetite Loss of appetiteA decreased appetite is when your desire to eat is reduced. The medical term for a loss of appetite is anorexia.Read Article Now Book Mark Article Pale skin (mild jaundice) Shortness of breath, mostly during exercise Shortness of breathBreathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough airImageRead Article Now Book Mark Article Heartburn Swollen, red tongue or bleeding gums If you have a low vitamin B12 level for a long time, you can have nervous system damage. Symptoms may include:Confusion ConfusionConfusion is the inability to think as clearly or quickly as you normally do. You may feel disoriented and have difficulty paying attention, remembe...ImageRead Article Now Book Mark Article Short-term memory loss Depression DepressionDepression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for shor...ImageRead Article Now Book Mark Article Loss of balance Numbness and tingling in the hands and feet Problems concentrating Irritability Hallucinations HallucinationsHallucinations involve sensing things such as visions, sounds, or smells that seem real but are not. These things are created by the mind.Read Article Now Book Mark Article Delusions Optic nerve atrophyOptic nerve atrophyOptic nerve atrophy is damage to the optic nerve. The optic nerve carries images of what the eye sees to the brain.ImageRead Article Now Book Mark Article Exams and Tests Your health care provider will perform a physical exam. Tests that may be done include: Complete blood count (CBC) Complete blood count (CBC)A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...ImageRead Article Now Book Mark Article Reticulocyte count Reticulocyte countReticulocytes are slightly immature red blood cells. A reticulocyte count is a blood test that measures the amount of these cells in the blood....ImageRead Article Now Book Mark Article Lactate dehydrogenase (LDH) level Lactate dehydrogenase (LDH)Lactate dehydrogenase (LDH) is a protein that helps produce energy in the body. An LDH test measures the amount of LDH in the blood.Read Article Now Book Mark Article Serum bilirubin Serum bilirubinThe bilirubin blood test measures the level of bilirubin in the blood. Bilirubin is a yellowish pigment found in bile, a fluid made by the liver. Bi...ImageRead Article Now Book Mark Article Serum methylmalonic acid (MMA) level Serum methylmalonic acid (MMAThe methylmalonic acid blood test measures the amount of methylmalonic acid in the blood.ImageRead Article Now Book Mark Article Homocysteine level (amino acid found in blood) Homocysteine level (amino acid found in...Homocystinuria is a genetic disorder that affects the metabolism of the amino acid methionine. Amino acids are the building blocks of all proteins i...ImageRead Article Now Book Mark Article Serum vitamin B12 level Serum vitamin B12 levelThe vitamin B12 level is a blood test that measures how much vitamin B12 is in your blood.Read Article Now Book Mark Article Levels of antibodies against IF or the cells that make IF Treatment The goal of treatment is to increase your vitamin B12 level: Treatment involves a shot of vitamin B12 once a month. People with severely low levels of B12 may need more shots in the beginning. Some people may be adequately treated by taking large doses of vitamin B12 supplements by mouth. A certain type of vitamin B12 may be given through the nose. Outlook (Prognosis) Most people often do well with treatment.It is important to start treatment early. Nerve damage can be permanent if treatment does not start within 6 months of symptoms. Possible Complications People with pernicious anemia may have gastric polyps. They are also more likely to develop gastric cancer and gastric carcinoid tumors.Gastric cancerStomach cancer is cancer that starts in the stomach.ImageRead Article Now Book Mark Article People with pernicious anemia are more likely to have fractures of the back, upper leg, and upper forearm.Brain and nervous system problems may continue or be permanent if treatment is delayed.A woman with a low B12 level may have a false positive Pap smear. This is because vitamin B12 deficiency affects the way certain cells (epithelial cells) in the cervix look. When to Contact a Medical Professional Contact your provider if you have symptoms of vitamin B12 deficiency. Prevention There is no known way to prevent this type of vitamin B12 anemia. However, early detection and treatment can help reduce complications.Open ReferencesReferencesAntony AC. Megaloblastic anemias. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 40.Anusha V. Pernicious anemia/megaloblastic anemia. In: Kellerman RD, Rakel DP, Heidelbaugh JJ, Lee EM, eds. Conn's Current Therapy 2024. Philadelphia, PA: Elsevier; 2024:491-493.Elghetany MT, Banki K. Erythrocytic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 33.Means Jr. RT. Approach to the anemias. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 144.Stabler SP. Megaloblastic anemias. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 150.